Threading device for sewing machine



YASUKATA EGUCHI 3,485,194

THREADING DEVCE FOR SEWING MACHINE 6 Sheets-Sheet 1 Dec. 23, 1969 Filed March 27, 196'? INVENTOR. M f

Dec. 23, 1969 YASUKATA @Guck-al 3,485,194

THREADING DEVICE FOR SEWING MACHINE 6 Sheecs-Shee'fI 2 Filed March 2'. 1967 INVENTOR. I (fm W WMM/PM Dec. 23, 1969 YSUKATA GUc-ax 39485194 THREDING DEVICE FOR SEWING MACHINE Filed March 27, 1967 6 Sheets-Sheet 5 INVENTOR.

D. 23, 1969 YASUKATA EGUCHI 3,485,194

THREADING DEVICE FOR SEWING MACHINE 6 Sheets-Sheet 5 Filed March 27, 1967 INVENTOR. /Mf-K was BY MM .S M

Dec, 23, w69 YASUKAM EGUCHI 3,485,194

THREADING DEVICE FOR SEWING MACHINE T' -ed March 27, 196'? 6 Sheets-Sheet 6 MF1- 7 JT 8 United States Patent O 3,485,194 THREADING DEVICE FOR SEWING MACHINE Yasukata Eguchi, Tokyo, Japan, assignor to Janome Sewing Machine Co., Ltd., Tokyo, Japan Filed Mar. 27, 1967, Ser. No. 628,516 Int. Cl. D05b 87/02 US. Cl. 112-225 13 Claims ABSTRACT OF THE DISCLOSURE A threading lever with an inserting hook is pivotally mounted on a support bar and normally retracted into the sewing machine housing. When a finger piece is moved to a first position, the support bar and the threading lever are advanced into the region of the needle, and when the finger piece is moved to a second position against the action of a spring, the threading lever is turned by an operating rod to a thread inserting position in which the hook is located in the needle eye.

BACKGROUND OF THE INVENTION The present invention relates to a threading device for a sewing machine of the type in which a hook is inserted into the needle eye so that the thread has to be placed in the hook instead of in the needle eye, which facilitates the threading operation.

Threading devices for sewing machines are known; however, the constructions of the prior art are complicated, diiiicult to operate, and do not reliably achieve the automatic insertion of the hook into the needle eye.

SUMMARY OF THE INVENTION It is the object of the invention to provide a semi automatic threading device for a sewing machine which accomplishes by operation of a finger piece, the precise insertion of a thread inserting part into the eye of the needle of a sewing machine.

Another object of the invention is to provide a threading device for a sewing machine which, ywhen inoperative during use of the sewing machine, is completely retracted into the housing.

Another object of the invention is to accomplish all operations required of the threading device, by moving a single linger engaging piece along a straight path.

With these objects in view, the present invention relates to a threading device for a sewing machine having a needle bar support and a needle bar for holding a needle having an eye.

In accordance with the invention, a support means such as a support bar, is movably mounted on the needle bar support and carries at its lower end a pivot on which a threading means is mounted for turning movement. A manually operated means, including a finger piece, is movable from a retracted position of rest, preferably along the straight vertical path, to a first position for moving the support means with the threading means from a retracted position in the housing to an advanced but inoperative position in which a thread inserting part of the threading means7 for example, a hook, is located in the region of the needle eye. When the finger piece is moved to an operative position, the threading means is turned from a normal inoperative position to a thread inserting position in which the thread inserting part is located in the needle eye.

In the preferred embodiment of the invention, the sewing machine housing has a slot through which the finger piece projects. Resilient means connect the lower end of the support means with a fixed point of the sewing machine, for example, with the needle bar support and urges the support means with the threading means into lll ICC

the housing so that the force of this spring has to be overcome for moving the support means with the threading means to the advanced inoperative position.

Preferably, the threading means is a lever carrying at one end` the thread inserting hook and being connected at the other end to an operating rod which is controlled by --the'finger piece for moving the threading lever to the. thread inserting position. Spring means operatively connect the operating rod with the finger piece so that the spring means is manually stressed when the thread inserting hook is located in the needle eye, and biases the operating rod to return the thread inserting lever to the normal position in which the thread inserting hook is located outside of the needle eye.

This construction of the invention permits the operator to accomplish the insertion of the thread inserting hook into the needle eye by simply moving a finger piece downward along a straight path, while all parts return to the normal position of rest located within the housing of the sewing machine when the finger piece is released by the operator.

Due to the fact that all parts of the threading device are completely retracted during normal sewing operations, the sewing device does not obstruct in any way the sewing operation, or the view of the operator observing the sewing area. The possibility that the threading device catches a thread, or part of the sewn fabric, or that the operators fingers are hurt by the inserting hook when the device is not used, is completely excluded due to the complete retraction of the threading device into the housing.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view illustrating a portion of a sewing machine head provided with a threading device according to one embodiment of the invention;

FIG. 2 is a fragmentary perspective view illustrating another embodiment of the invention;

FIGS. 3 and 4 are fragmentary side elevations illustrating the embodiment of FIG. 2 in inoperative and operative positions;

FIG. 5 comprises three schematic views FIG. 5A, FIG. 5B, FIG. 5C illustrating three operational positions of the embodiment of FIGS. 2 to 4;

FIG. 6 is a fragmentary perspective view illustrating the embodiment of FIG. l;

FIGS. 7 and '8 are fragmentary side elevations illustrating the embodiment of FIG. 6 in inoperative and operative positions; and

FIG. 9 comprises three schematic views FIG. 9A, FIG. 9B, FIG. 9C illustrating three operational positions of the embodiment of FIGS. 6 to 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Although the embodiment of FIGS. 6 to 9 is shown mounted in the housing of the sewing machine in FIG. 1, it will be understood that the embodiment of FIGS. 2 to 5 is mounted in the same manner in the housing of the sewing machine.

Referring first to FIG. 1, the table 101 of the sewing machine carries the housing 100 which is closed by a front cover 93. A manual lever 95 in a slot 94 is used for raising and lowering the presser bar 97 with presser foot 98. An opening in table 101'is closed by a metal plate 99 provided with an opening through which a feed dog 96 projects for moving the fabric past the needle 17 and under the presser foot. A needle bar 15 carries a holder 16 for the sewing needle 17 which has an eye 17.

Referring now to FIGS. 2 to 5, the needle bar support 6 has bearing projections 6E and 6F in which needle bar 1S is mounted for vertical reciprocating movement. Needle bar is operated from a drive shaft 21 through a crank 18, a crank pin 19, and articulated linkage 22, 20, while the needle bar support 6 is mounted for pivotal movement on a pin 23 in a part 26 and controlled by an arm to perform a zig-zag movement. This arrangement is entirely conventional, and not an object of the present invention.

Needle bar support 6 has bearing projections 6A and 6B in which a support bar 5 is mounted for vertical movement parallel to needle bar 15. A holder 4 at the lower end of support bar 5 carries a pivot screw 1c on which an angular threading lever 1 is mounted for angular movement between an inoperative position shown in FIG. 2 and a thread inserting position shown in FIG. 4 in which a thread inserting hook 2 is located in the eye of needle 17.

A resilient means in the form of a long coil spring 11 connects holder 4 and pivot screw 1c with an attaching screw `6D on the upper part of needle bar support 6 so that the support means 5, 4 are urged to move upwards to the position shown in FIG. 3 in which linger piece 7 abuts stop 6a of the needle bar support 6.

A linger piece 7 is secured by a screw to support bar 5 and has a slide face 7B guided along a guide face 6C of needle bar support 6. A portion 7D projects out of a slot 92 in housing 100 to be accessible to the operator, but in FIG. 1 which illustrates another embodiment of the invention, the respective portion is indicated by reference numeral 7'D.

Finger piece 7 has a projection 7C with a transverse lug having a bore to which one end of a coil spring 9 is secured. The other end of the coil spring is attached to a bent portion of an operating rod 3 whose lower end is bent and inserted into a bore of an arm 1B of the threading lever 1.

As best seen in FIG. 4, a control lever 8 is mounted intermediate its ends for pivotal movement on finger piece 7 and support bar 5 and has one end portion 8B with a bore into which the bent-over end of operating rod 3 projects. The other end portion 8A cooperates with a control stop 14 lixed to the needle bar 15, as shown in FIG. 5. Another stop 12 is adjustably secured to needle bar support 6 and has an upper stop face located below the level of the upper stop face of control stop 14. Screws 13 are threaded into needle bar support 6 and pass through vertical slots 12A in stop 12 so that the position of stop 12 can be adjusted. The upper stop face of stop 12 cooperates with the lower face of linger piece 7, and stops downward movement of the same in the position of FIG. 4.

. The embodiment illustrated in FIGS. 2 to 5 is operated as follows. During normal sewing operations, when the threading device is not used, the threading device is held by spring 11 in the retracted position shown in FIGS. 3 and 5A so that only thread inserting hook 2 projects out of the housing, as shown in FIG. 1. It is, of course, possible to retract the device farther so that hook 2 is also located in the'housng. Finger piece 7 Iabuts bearing projection 6A, and spring 9 pulls control lever 8 to a horizontal position, and operating rod 3 to a first position in which threading lever 1 is in an inoperative position with hook 2 transversely retracted from the needle bar and needle 17, as shown in FIG. 3.

When it is 'desired to insert a thread, the operator depresses the projecting portion 7D of the linger piece, and moves the same, together with support bar 5, from the retracted position of rest illustrated in FIG. 3 to an ad- Vvanced inoperative position illustrated in FIG. 5B. In

this position, linger piece 7 is spaced from stop 12, but the engaging portion -8A of lever 8 touches stop 14. When finger piece 7 is further depressed to an operative position in which it abuts stop 12, engaging portion 8A cannot follow the downward movement since it abuts on the top face of stop 14 so that lever 8 turns an angle to the slanted position shown in FIG. 4 in which spring 9 is tensioned, and operating rod 3 is lowered to a second position to turn threading lever 1 an angle a which is equal to the angle When linger piece 7 arrives in the advanced inoperative position shown in FIG. 5B, support bar 5 with threading lever 1 is loweredl to a position in which hook 2 is located opposite, but trarisversely spaced from the needle eye 17', as shown in FIG. 5B and FIG. 2. Consequently, upon movement of linger piece 7 to the operative position abutting stop 12, threading lever 1 is turned to the position of FIG. 4 and FIG. 5C in which thread inserting hook 2 passes through the needle eye 17 so that a thread can be inserted into the hook.

When the linger piece 7 is released by the operator, it moves upward a small distance permitting lever 8 to turn in clockwise direction under the action of the contracting spring 9 so that operating rod 3 is raised slightly, and threading lever 1 is turned in clockwise direction until hook 2 is located outside of the needle eye. p

Spring 11 pulls the entire threading device including support ibar 5, operating rod 3, threading lever 1 and linger piece 7 upward to the retracted position of rest shown in FIG. 3 and FIG. 5A in which linger piece 7 abuts bearing projection 6A. Hook 2 is either located in the housing, or slightly below the same as shown in FIG. 1, and cannot interfere with the sewing operations. While hook 2 is transversely retracted from the needle eye, it pulls the thread therein through the needle eye so that a sewing operation can be started.

During the above-described operation of the threading device, the needle bar 15 is placed in the upper dead center position so that the point and eye of needle 17 are located above the surface of table 101 and in the proper relative position to threading means 1, 2 so that inthe position of FIG. 5B, the thread inserting hook 2 is aligned with the eye in needle 17.

Referring now to the embodiment shown in FIGS. l and 6 to 9, the general arrangement is as described with reference to the embodiment of FIGS. 2 to 5, and corresponding parts are indicated by the same reference numerals.

The angular threading lever 1 is again mounted for pivotal movement at the lower end of support bar 5, and has an arm pivotally connected with an operating rod 3. However, operating rod 3 is directly connected with a projecting portion 7'C of linger piece 7. Finger piece 7' is not lixed to support bar 5, but slidable on the same. A lirst abutment 28 is secured to support bar 5 below linger piece 7, and a coil spring 29 abuts abutment 28 and linger piece 7 to urge the same upward into engagement with a second abutment 10 secured to support bar 5. A portion 7'D of finger piece 7 projects out of slot 92 of housing and is used by the operator. A slide face 7B is guided along guide surface 6C of needle bar support 6. Spring 11 connects the holder 4 of the support bar 5 with an attaching means 6D and urges the entire device upward to a retracted position shown in FIG. 1. A control stop 14 is secured to the needle bar 15 and cooperates with a stop portion 10C of abutment 10 on support bar 5.

The threading device illustrated in FIGS. 1 and 6 to 9 is operated las follows: The needle bar 15 with needle 17 is placed in the highest position which can be easily determined by observing the reciprocating motion of the needle, or of the thread take-up lever. In the position of rest, spring 11 retracts the entire device into the housing of the sewing machine, as shown in FIG. 1 and FIG. 9A. When nger piece 7 is depressed by the operator, spring 29 is strong enough to transmit the force to abutment 28 so that support bar 5 moves downward together with threading lever 1 and thread inserting hook 2 to an advanced inoperative position shown in FIG. 9B in which stop portion 10C abuts control stop 14 so that abutment 10, support bar 5, and threading means 1, 2 are stopped in an advanced position in which thread inserting hook 2 is aligned with the needle yWhen pressure on finger piece 7 is continued, the same moves from the advanced inoperative position shown in FIG. 9B to the operative position shown in FIGS. 9C and 8. Since support bar 5 is prevented from downward movement by the engagement between abutment and control stop 14, spring 29 is compressed so that finger piece 7 can further move to the lower operative position shown in FIG. 9C and move operating rod 3 downward until nger piece 7 abuts stop 12 on needle bar support 6, as shown in FIG. 8. During this movement threading lever 1 is turned to the thread inserting position in which hook 2 is located in the needle eye. A thread is inserted into the hook, and when finger piece 7' is released by the operator, it is moved upward by the expanding spring 29 so that the hook 2 is retracted from the needle eye since threading lever 1 turns in clockwise direction. In this manner, the thread is placed in the eye of needle 17, and can be removed from hook 2. The released iinger piece 7 abuts abutment 10 under the action of spring 29, and the entire threading device is pulled upward by spring 11 until abutment 10 abuts the bearing projection 6A of needle `bar support 6 as shown in FIG. 7. The retracted position of FIG. 7 is again assumed, and the machine is ready for a sewing operation with a newly inserted thread.

In the event that the sewing machine is of the type employing multiple needles, a corresponding number of threading levers 1 is mounted on support bar 5, and simultaneously operated as explained above by operating rods 3 connected with finger piece 7 or 7.

From the above descriptions of preferred embodiments of the invention, it will become apparent that the manually operated means including finger piece 7, 7' are operable between a retracted position of rest shown in FIGS. 5A and 9A to a first advanced inoperative position shown in FIGS. 5B and 9B in which support means 5 is advanced with threading means 1, 2 to an advanced position in which hook 2 registers with the needle eye 17, and further to an operative position shown in FIGS. 5C and 9C in which operating means 3 turns threading means 1, 2 to the thread inserting position while spring means 9, 29 are stressed. The advanced inoperative position of the manually operated means 7, 7 is determined by a control stop 14, and the operative position determined by stop 12. When the control member 8 or 10 engages stop 14, spring 9 or 29 is stressed and tends to withdraw threading means 1, 2 from the needle eye, which is effected when the operator releases the manually operated means. Control members 8 and 10, and springs 9 and 29, are parts of control means engaging control stop 14 for obtaining a relative movement between operating rod 3 and support bar S by which threading means 1, 2 is turned to the thread inserting position shown in FIGS. 5C and 9C.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of threading devices for sewing mechines differing from the types described above.

While the invention has been illustrated and described as embodied in a threading device retractable into the housing of a sewing machine, and being operated by straight movement of a nger piece to insert a hook into the needle eye, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

What is claimed is:

1. In a sewing machine having a supporting structure including a needle bar support, and a needle bar mounted on the same for holding a needle having an eye, a threading device comprising a support element having a first pivot means; a threading means having a thread inserting means and being mounted on said first pivot means for turning movement between an inoperative position, and a thread inserting position for placing said thread inserting means in said eye; means mounting said support element on said needle bar support for movement with said threading means between a retracted position, and an advanced position in which said thread inserting means registers with said eye; an operating element having a second pivot means connected with said threading means and being movable relative to said support element for turning said threading means from said inoperative position to said thread inserting position; manually operated means secured to one of said elements and being movable from a retracted position to an advanced inoperative position and to an operative position; spring means connecting said manually operated means with the other of said elements so that movement of said manually operated means to said advanced inoperative position causes movement of said support element and said operating element together until said support element is in said advanced position', stop means on said needle bar; control means mounted on said support element engaging said stop means in said advanced position of said support element so that further movement of said manually operated means to said operative position causes movement of said operating element relative to said support element while said spring means is manually stressed so that said threading means is turned from said inoperative position to said thread inserting position.

2. A threading device as claimed in claim 1 wherein said sewing machine comprises a housing having a slot; wherein said support elementand said threading means are substantially located within said housing in said retracted position; and wherein said manually operated means include a finger piece projecting through said slot out of said housing.

3. A threading device as claimed in claim 2 and compn'sing resilient means connecting said support means element with said needle bar support and urging said support element with said threading means to said retracted position in said housing upon release of said manually operated means by the operator.

4. A threading device as claimed in claim 1 wherein said manually operated means is secured to said support element, and connected by said spring means with said operating element; and wherein said control means includes a control lever pivotally mounted on said support element, and a pivot connecting said control lever with said operating element so that said operating element moves relative to said support element when said control lever abuts said stop means and is turned during movement of said manually operated means to said operative position.

5. A threading device as claimed in claim 1 wherein said manually operated means is secured to said operating element, and connected by said spring means with said support element; and wherein said control means includes a control stop secured to said support element so that said operating element moves relative to said support element when said control stop abuts said stop means during movement of said manually operated means to said operative position.

6. A threading device as claimed in claim 1 wherein said support element includes a support bar mounted on said needle bar support for movement along a straight path; wherein said operating element include an operating rod mounted on said support bar for movement along a straight path; and wherein said manually operated means moves with said one element along a straight path.

7. A threading device as claimed in claim 6 wherein said support bar and said operating rod are upright and move parallel vto said needle bar, and have said rst and second pivot means on the lower ends thereof, respectively; wherein said control means is mounted on the upper end of said support bar; and wherein said threading means includes a lever having said second pivot means at one end and said thread inserting means at the other end.

8. In a sewing machine having a supporting structure including a needle bar support, and a needle bar mounted on the same for holding a needle having an eye, a threading device comprising a support bar mounted on said needle bar support for straight movement parallel to said needle bar between a retracted position and an advanced position, and having a rst pivot means at one end; a threading means having a thread inserting part and being mounted on said rst pivot means for turning movement between an inoperative position, and a thread inserting position for placing said thread inserting part in said eye, and also for movement in said inoperative position with said support bar to said advanced position in which said thread inserting part is located in the region of said eye when said needle bar is in a selected position; operating means including an operating rod mounted on said support bar for straight movement relative to the same and parallel to said needle bar between first and second positions, and having at one end a second pivot means connected with said threading means at a point spaced from said rst pivot means so that said threading means is turned from said inoperative position to said thread inserting position when said operating rod moves from said first position to said second position relative to said support bar; manually operated means movable from a retracted position to an advanced inoperative position and to an operative position; stop means on said needle bar; control means engagea-ble with said stop means and operatively connecting said manually operated means with said support bar and said operating rod and including spring means so that said manually operated means when moved from said retracted position to said advanced inoperative position moves said support bar, and said operating rod in said rst position, together until said control means engages said stop means and said support bar arrives in said advanced position, and so that further movement of said manually operated means to said operative position causes movement of said operating rod relative to said support bar to said second position while said spring means is manually stressed whereby said threading means is turned from said inoperative position to said thread inserting position in which said spring means biasses said thread inserting means to return to said inoperative position.

9. A threading device as claimed in claim 8 wherein said sewing machine comprises a housing having a vertical slot; wherein said operating rod, said support bar and said threading means are located within said housing in said retracted position; wherein said manually operated means includes a linger piece projecting through said slot out of said housing; wherein said support bar and said operating rod are mounted for straight vertical movement; and comprising resilient means connecting the lower end of said support bar with said needle bar support for urging said support bar with said threading means and manually operated means into said retracted position upon release of said linger piece by the operator.

10. A threading device as claimed in claim 8 wherein said manually operated means includes a finger piece iixedly secured to said support bar for moving the same from said retracted to said advanced position during movement of said nger piece from said retracted position to said advanced inoperative position; wherein said control means include a lever pivotally mounted on said finger piece and connected with said operating rod; wherein said spring means connects said finger piece with said operating rod; said stop means comprises a control stop mounted on said needle bar and engaged by said lever during movement of said manually operated means from said advanced inoperative position to said operative position so that said lever turns and moves said operating rod against the action of said spring means to turn said threading means from said inoperative position to said thread inserting position.

11. A threading device as claimed in claim 10 wherein said spring means is a tension spring connecting said finger piece -with the upper end of said operating rod; wherein said lever is pivotally connected with said upper end of said operating rod; wherein said threading means is an angular lever having one arm carrying said thread inserting part and another arm pivotally connected with said operating rod; and comprising a stop on said needle bar support for stopping said nger piece in said operative position whereby said threading means is stopped in said thread inserting position.

12. A threading device as claimed in claim 8 wherein said manually operated means include a nger piece connected with said operating rod and movably mounted on said support bar; wherein said control means comprise rst and second abutments on said support bar; wherein said finger piece is located between said iirst and second abutments; wherein said spring means connects said rst abutment and said finger piece so that during movement of said finger piece from said retracted position to said advanced inoperative position, said spring means transmits the motion to said support bar for moving the same with said threading means to said advanced position; and said stop means comprises a control stop on said needle bar engaged by said second abutment in said advanced inoperative position of said finger piece so that movement of said support bar is stopped in said advanced position whereby said iinger piece, when moved to said operative position relative to said stopped support bar against the action of said spring means, moves said operating rod to turn said threading means from said inoperative position to said thread inserting position.

13. A threading device as claimed in claim 12 wherein said spring means is a coil spring surrounding said support bar abutting said rst abutment and said iinger piece, and being compressed in said operative position of said nger piece; wherein said nger piece is lixed on said operating rod; wherein said threading means is an angular lever having one arm carrying said thread inserting part, and another arm pivotally connected with said operating rod; and comprising a stop on said needle bar support for stopping said finger piece in said operative position whereby said threading means is stopped in said thread inserting position.

References Cited UNITED STATES PATENTS RICHARD l, SCANLAN, JR., Primary Examiner 

